1-2-1 Some help please

Hello,

Just some questions on this pattern, which I think is a good one for me to study.

1. How does one determine good pattern structure? Is it to do with having the Fib ratios as close to perfect as possible? Or is it about having a pattern without too much noise between pivots?
2. What is a reliable confirmation for 1-2-1? So many to choose from, but I need a reliable one. Has anyone tested different confirmations statistically?